If it were not clear before, a Rockets team built to take down the champs saw up close, vividly and undeniably, just how tough that will be.

The Rockets were far from their best Monday night. They could point to many things they could correct. Yet when they hit Golden State early, the Warriors hit back harder. When the Rockets gave chase late, the Warriors rolled.

When the Rockets brought in all of James Harden’s offensive magnificence, the Warriors came with waves of stars until every Rockets misstep, every lull was too much to overcome as Golden State took a convincing 119-106 win for a 1-0 Western Conference finals lead that captured the home-court advantage the Rockets spent six regular-season months securing.

The Warriors, however, demonstrated how small a margin of error they will allow, with every missed defensive rotation seeming to lead to an open 3-pointer, turnovers leading to dunks, missed layups leading to open 3s.

18 misses from paint

The Rockets averaged 9.7 turnovers in the first two rounds of the playoffs. They had 16 on Monday. They missed shots at the rim, coming up empty on 18 shots in the paint. But worse than what that cost them on their end, it sent the Warriors flying the other way.

“They did a really good job. If you take bad shots or turn the ball over, they’re out,” Harden said. “They’re getting dunks. They’re getting 3s. I’m not sure how many transition points they had (18), but it was too many. We have to do a better job of not turning the ball over, taking better shots and getting back and matching up. There were a couple times we didn’t guard anybody. They got a dunk or an open 3. That can’t happen.”

Giving the Warriors that much of a running start, the Rockets could not keep pace. Harden had hit them with an early haymaker, rushing the Rockets to a nine-point lead, but Golden State was consistently getting open looks and by halftime had tied the game at 56.

Harden finished with 41 points and seven assists, burning the Warriors’ switching defenses by going one-on-one. But the Rockets often bogged down badly, having to race to beat the shot clock.

Other than Harden and Chris Paul, who added 23 points, the Rockets made just 17 of 44 shots (38.6 percent). That would not be nearly enough, with the Warriors so deep with answers for the Rockets’ top scorers.

Mental mistakes add up

That began with Kevin Durant, who answered the Rockets’ early burst and consistently shot over their defenders, making 14 of 27 shots to score 37 points. But that was to be expected. The waves of other shots too good to regularly miss were too much to overcome.

Klay Thompson hit six of 15 3-pointers to score 28 points. Stephen Curry had 18 points but was general kept in check, making just one of five 3-pointers. But even that seemed to show how many ways Golden State was able to score and how many Warriors the Rockets left available.

“They’re obviously champions for a reason,” Rockets coach Mike D’Antoni said. “If we want to beat them, we have to be mentally sharper. KD, he’s tough. Hey, you can live with that. But you can’t live with that and then make mental mistakes, and that’s what we do. The combination of the two was devastating.”

Even when the Rockets overcame most of a 13-point Warriors lead late in the third quarter, closing within four, they could not lock down often enough to make a run last. The Warriors made four of their next five shots, with Thompson hitting a pair of 3s before Durant returned to hit another from 28 feet, rushing through a 13-4 run to take control of the game while the Rockets misfired through just a few too many minutes.

“We had a lot of makeable shots,” Paul said. “That happens in a given game. Defensively, we have to be better. Some games, some series, you may make those mistakes and guys don’t make the shots. Tonight, every time we did it, they made the shots. They make you pay when you make mistakes. Every time we made a mistake, they made us pay.”

With that, it was clear what the Rockets are up against. It likely was before, but now that has become obvious as the peril of a 1-0 hole in the series.

Jonathan Feigen has been the Rockets beat writer since 1998 and a basketball nut since before Willis Reed limped out for Game 7. He became a sports writer because the reporter that was supposed to cover the University of Delaware basketball team decided to instead play one more season of college lacrosse and has never looked back.

Feigen, who has won APSE, APME and United States Basketball Writers Association awards from El Campo to Houston, came to Texas in 1981 to cover the Rice Birds, was Sports Editor in Garland before moving to Dallas to cover everything from the final hurrah of the Southwest Conference to SMU after the death penalty.

After joining the Houston Chronicle in 1990, Feigen has covered the demise of the SWC, the rise of the Big 12 and the Rockets at their championship best.